Compact Dual-Band Dual-Mode SIW Balanced BPF With Intrinsic Common-Mode Suppression

• Published in: IEEE microwave and wireless components letters 2021-02, Vol.31 (2), p.101-104
• Main Authors: Han, Yang-Kun, Deng, Hong-Wei, Zhu, Jia-Ming, Xing, Si-bei, Han, Wei
• Format: Article
• Language: English
• Subjects: Balanced filter; Band-pass filters; Bandpass filters; Dual band; high common-mode (CM) suppression; Microstrip; multi-mode resonator; Nonhomogeneous media; Passband; Perturbation; Pins; substrate integrated waveguide (SIW); Substrate integrated waveguides; Substrates
• ISSN: 1531-1309; 2771-957X; 1558-1764; 2771-9588
• DOI: 10.1109/LMWC.2020.3048977

In this letter, a compact dual-band dual-mode substrate integrated waveguide (SIW) balanced band-pass filter (BPF) with intrinsic common-mode (CM) suppression is designed by using a single perturbed SIW circular cavity. The vias and slot perturbations are introduced to tune the resonant modes TE 010 , TE 110 (a pair of degenerate modes), and TE 210 of a circular cavity. Thus, they can be used to form two differential-mode (DM) passbands with independently adjustable center frequencies and bandwidths. The SIW can be seen as a natural balun with intrinsic CM suppression. Furthermore, the planar differential excitation structure is designed to excite the perturbed SIW cavity. The CM noise cannot excite SIW cavity due to the characteristics of hybrid electromagnetic boundary. Finally, a compact dual-band dual-mode SIW balanced BPF at 8 and 10 GHz is designed and fabricated, and the measured results show good agreement with the simulated ones.